 Both proteins bind to Cdc31p, the yeast centrin homolog, which also localizes to the half-bridge and is required for half-bridge integrity.An additional half-bridge component, Sﬁ1p, shows ability to bind to Cdc31p through multiple conserved Cdc31-binding sites throughout its length.Kar1p is also involved in connecting the half-bridge to the core SPB via its interaction with Bbp1p.